4.18-stable review patch. If anyone has any objections, please let me know.
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From: Eugeniy Paltsev Eugeniy.Paltsev@synopsys.com
commit db05c481977599236f12a85e55de9f5ab37b0a2c upstream.
drm fbdev emulation doesn't support changing the pixel format at all, so reject all pixel format changing requests.
Cc: stable@vger.kernel.org Signed-off-by: Eugeniy Paltsev Eugeniy.Paltsev@synopsys.com Reviewed-by: Ville Syrjälä ville.syrjala@linux.intel.com Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch Link: https://patchwork.freedesktop.org/patch/msgid/20181003164538.5534-1-Eugeniy.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/drm_fb_helper.c | 91 +++++++++++----------------------------- 1 file changed, 26 insertions(+), 65 deletions(-)
--- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1561,6 +1561,25 @@ unlock: } EXPORT_SYMBOL(drm_fb_helper_ioctl);
+static bool drm_fb_pixel_format_equal(const struct fb_var_screeninfo *var_1, + const struct fb_var_screeninfo *var_2) +{ + return var_1->bits_per_pixel == var_2->bits_per_pixel && + var_1->grayscale == var_2->grayscale && + var_1->red.offset == var_2->red.offset && + var_1->red.length == var_2->red.length && + var_1->red.msb_right == var_2->red.msb_right && + var_1->green.offset == var_2->green.offset && + var_1->green.length == var_2->green.length && + var_1->green.msb_right == var_2->green.msb_right && + var_1->blue.offset == var_2->blue.offset && + var_1->blue.length == var_2->blue.length && + var_1->blue.msb_right == var_2->blue.msb_right && + var_1->transp.offset == var_2->transp.offset && + var_1->transp.length == var_2->transp.length && + var_1->transp.msb_right == var_2->transp.msb_right; +} + /** * drm_fb_helper_check_var - implementation for &fb_ops.fb_check_var * @var: screeninfo to check @@ -1571,7 +1590,6 @@ int drm_fb_helper_check_var(struct fb_va { struct drm_fb_helper *fb_helper = info->par; struct drm_framebuffer *fb = fb_helper->fb; - int depth;
if (var->pixclock != 0 || in_dbg_master()) return -EINVAL; @@ -1591,72 +1609,15 @@ int drm_fb_helper_check_var(struct fb_va return -EINVAL; }
- switch (var->bits_per_pixel) { - case 16: - depth = (var->green.length == 6) ? 16 : 15; - break; - case 32: - depth = (var->transp.length > 0) ? 32 : 24; - break; - default: - depth = var->bits_per_pixel; - break; - } - - switch (depth) { - case 8: - var->red.offset = 0; - var->green.offset = 0; - var->blue.offset = 0; - var->red.length = 8; - var->green.length = 8; - var->blue.length = 8; - var->transp.length = 0; - var->transp.offset = 0; - break; - case 15: - var->red.offset = 10; - var->green.offset = 5; - var->blue.offset = 0; - var->red.length = 5; - var->green.length = 5; - var->blue.length = 5; - var->transp.length = 1; - var->transp.offset = 15; - break; - case 16: - var->red.offset = 11; - var->green.offset = 5; - var->blue.offset = 0; - var->red.length = 5; - var->green.length = 6; - var->blue.length = 5; - var->transp.length = 0; - var->transp.offset = 0; - break; - case 24: - var->red.offset = 16; - var->green.offset = 8; - var->blue.offset = 0; - var->red.length = 8; - var->green.length = 8; - var->blue.length = 8; - var->transp.length = 0; - var->transp.offset = 0; - break; - case 32: - var->red.offset = 16; - var->green.offset = 8; - var->blue.offset = 0; - var->red.length = 8; - var->green.length = 8; - var->blue.length = 8; - var->transp.length = 8; - var->transp.offset = 24; - break; - default: + /* + * drm fbdev emulation doesn't support changing the pixel format at all, + * so reject all pixel format changing requests. + */ + if (!drm_fb_pixel_format_equal(var, &info->var)) { + DRM_DEBUG("fbdev emulation doesn't support changing the pixel format\n"); return -EINVAL; } + return 0; } EXPORT_SYMBOL(drm_fb_helper_check_var);